Metabolic acidosis is one of the metabolic complications of chronic kidney disease (CKD). Correction of metabolic acidosis in CKD has been shown to prevent further loss of kidney function over time. Currently, a clinical trial (the BIC-study, MEC-2013-332) is conducted in which patients with CKD and metabolic acidosis receive sodium bicarbonate, sodium chloride, or no treatment (time control) to address the hypothesis that the beneficial effects of acidosis correction are mediated through inhibition of the intrarenal renin-angiotensin system (RAS). It is unknown, however, if and how acute changes in acid-base status affect the intrarenal RAS during CKD. In the present study it is hypothesized that an acute acid load increases the activity of the intrarenal RAS, and that this response is exaggerated in patients with CKD compared with healthy controls.
